Related Clues:

• __-sea
• ___ blue sea
• Worth thinking about
• Like the 10-foot end of the pool
• Way down
• Profoundly
• Filled with import
• Seemingly bottomless
• Hardly superficial
• Like the sea
• Like some pockets
• Low in pitch
• Difficult to fathom
• In need of coffee, maybe
• Up to one's eyeballs